Method for detecting in situ weak absorption optical thin film thickness in thin film growth

The invention discloses a method for detecting in situ weak absorption optical thin film thickness in thin film growth, which comprises the following steps that: a layer of backing film with the thickness enough for producing interference is plated as a substrate, and the thin film thickness can be measured by measuring the changes of transmission (reflection) spectrum before and after film plating. Because of the thickness of the backing film produces interference, even if the thin film to be measured which is newly plated is very thin, the interference is changed; the thickness of the thin film to be measured can be easily and accurately measured through the changes to the transmission (reflection) spectrum before and after the plating of the thin film to be measured, and the measurement limit is above 3nm. The method can accurately measure the thickness of a nano ultra-thin film so that the thickness of the thin film to be measured can be quickly obtained only by measuring the transmission ...